Mushroom Swiss Recipe

Form patties

Divide the 1 lb ground beef into two equal portions (approx. 8 oz each). Gently form each portion into a patty about 3/4"–1" thick and slightly wider than the bun. Do not overwork the meat to keep patties tender.

Season both sides of each patty with kosher salt and freshly ground black pepper. If using, brush or mix 1 tablespoon Worcestershire sauce into the meat before forming for extra flavor.

Heat a large skillet over medium-high heat. Add 1 teaspoon olive oil and 1 tablespoon butter. When butter foams, add the thinly sliced mushrooms and 1/2 cup sliced onion in an even layer.

Cook, stirring occasionally, until mushrooms give off liquid and begin to brown, about 6–8 minutes. Add 1 clove minced garlic and 1 teaspoon fresh thyme; cook 30–45 seconds until fragrant.

Stir in 1 teaspoon soy sauce, then reduce heat to medium. Season with 1/4 teaspoon salt and 1/8 teaspoon black pepper. Continue to cook until onions are soft and mushrooms are nicely caramelized, another 2–3 minutes. Remove from heat and keep warm.

Preheat a heavy skillet or griddle over medium-high heat for the patties. Meanwhile, spread 1 tablespoon butter across cut sides of the buns.

Toast buns, buttered side down, in a clean skillet or on the griddle until golden and crisp, about 1–2 minutes. Remove and set aside, buttered sides up.

With the skillet or griddle hot, place patties on it. Cook without moving for 3–4 minutes to form a crust. Flip and cook another 3–4 minutes for medium doneness (internal temp ~160°F/71°C for ground beef), or longer/shorter to your preferred doneness.

About 1 minute before the patties are done, place a slice of Swiss cheese on each patty and cover the skillet with a lid or a large bowl to trap steam and help the cheese melt, about 30–60 seconds.

Spread 1 teaspoon mayonnaise on the bottom bun and 1/2 teaspoon Dijon mustard on the top bun, if using.

Place the lettuce leaf on the bottom bun, then place the cheesy patty on top of the lettuce.

Spoon a generous portion (about 1/2 cup) of the warm mushroom and onion mixture over the cheese-topped patty.

Add tomato slices and optional raw onion rings on top of the mushrooms. If using, place cooked bacon slices over the tomato.

Cover with the top bun, press gently to compact, and serve immediately.

Serve with your choice of sides (fries, chips, or a side salad). Leftover mushroom mixture keeps refrigerated up to 3 days; reheat gently before using.